Abstract:
Climate warming is occurring in high-mountain areas at a faster rate than the global average. To escape the increasing temperatures, alpine species may shift in distribution upwards, threatening cold-adapted nival plant specialists. However, little is known about the success of seedling emergence and establishment at high altitudes outside the current range, particularly in the highest mountain areas of the Himalayas. We selected four native alpine species occurring around 4000 m a.s.l. and sowed seeds at the natural growing site (GS), at a high elevation site (HS; 5000 m a.s.l.) and at high elevation with soil from the growing site (HS-S) in the Khumbu Valley, north-eastern Nepal. We monitored seedling emergence and establishment for two consecutive years. Seedling emergence and establishment varied between species. Emergence was similar between GS and HS and improved at HS-S. Establishment was low at high elevations with all but one species having high mortality after winter. Seedling emergence of low elevation plants is possible at high elevations in the Everest region, indicating species may be able to shift their distribution range upwards. However, successful establishment may be limited by the soil and high winter mortality at high elevations, although not in all species. Climate warming will potentially lead to upward migration of some Himalayan plant species, leading to altered community composition in high-mountain areas.
摘要:
高山地区的气候变暖速度快于全球平均水平。为了逃避不断升高的温度,高山物种的分布可能会向上移动,威胁寒冷的狂欢节植物专家。然而,关于在当前范围之外的高海拔地区幼苗出苗和建立的成功知之甚少,特别是在喜马拉雅山的最高山区。我们选择了大约4000ma.s.l.的四种本地高山物种。并在自然生长地点(GS)播种种子,在高海拔地点(HS;5000ma.s.l.)和高海拔地区,土壤来自昆布山谷的生长地点(HS-S),尼泊尔东北部。我们连续两年监测幼苗出苗和成苗。幼苗的出现和建立因物种而异。GS和HS的出现相似,HS-S有所改善。高海拔地区的建立率很低,除一个物种外,所有物种在冬季后的死亡率都很高。珠穆朗玛峰地区高海拔地区可能出现低海拔植物的幼苗,表明物种可能能够向上移动它们的分布范围。然而,成功的建立可能受到高海拔地区土壤和冬季高死亡率的限制,虽然不是所有物种。气候变暖可能会导致一些喜马拉雅植物物种的向上迁移,导致高山地区社区组成发生变化。